Apple says the iOS 9 software for its iPhones, iPads and iPod touch devices is now on 66% of those products, which means the new edition of iOS is off to a faster adoption rate than last year's iOS 8.

The software was released in mid-September, and adoption is up from 52% shortly after that. Apple said in early November last year that iOS 8 was on 56% of devices after being released in mid-September. One reason for iOS 9's fast adoption is that it takes up less space on devices, so is more easily downloaded.

Of course, not all iOS 9 features have been met with a universally warm reception. Some have complained that the on-by-default Wi-Fi Assist feature has been chewing up their data allotments by switching from Wi-Fi to cellular connectivity willy-nilly, and a class action lawsuit has even been filed against Apple over it.

New this week is Apple's release to developers of the second iOS 9.2 beta version, which includes support for AT&T's NumberSync Wi-Fi calling service on Macs. Other enhancements are more under the hood, and are aimed at boosting performance and fixing bugs.

Bob Brown is a news editor for Network World, blogs about network research, and works most closely with our staff's wireless/mobile reporters. Email me at bbrown@nww.com with story tips or comments on this post. No need to follow up on PR pitches via email or phone (I read my emails and will be in touch if interested, thanks)